Traditionally composite parts have been manufactured via labour intensive hand lay-up process, by a skilled laminator. In known methods, a base material for the lay-up, in the form of either pre-preg or dry fibre composite material, is laminated into a mould tool, which matches the geometry of the final component, so that the base material is formed directly into the shape of the final part. Using this approach enables complex geometries to be achieved as the laminators' skill is used to tailor the material into the contours of the component. However hand lay-up does not enable high deposition rates of material.
In all market sectors there is a desire to reduce the overall manufacture process time throughout all steps in the production of a cured composite part. Particularly for large scale or thick components having may plies, and particularly within the Aerospace sector, this has resulted in the development of automated deposition processes for all material formats, such as: Automated Fibre Placement (AFP), Automated tape lay-up (ATL) and Dry Fibre AFP (DAFT). However these complex deposition systems have limitations, primarily with respect to the geometrical shapes which they are able to create, due to the large physical size of the end effector that delivers the material onto the tool. For components where the geometry is “simple” and generally flat, there is less of a problem with access for the end effector. An example is in the formation of a composite wing skin part.
For more integrated structures, and for components with more complex shapes, the size of the end effector can prevent it from depositing inside cavities or recesses in the shape of the lay-up, since the end effector my not fit or be able to reach between two opposing walls of the feature or features, for example. This necessitates further processing of the un-cured laminate structure (also known as a preform) to generate the final shape. Typically this additional processing is reliant on a method of forming, e.g. in a press or a mould, the laminated preform into the desired shape prior to curing. All forming process require the use of heat, pressures and additional mould tooling or consumables, which adds to the overall process time and cost.
Many parts of aircraft structures would traditionally be manufactured from a number of separate parts which are then joined together via mechanical fasteners to create the overall structure. The mechanical bolting of joints in composite structures is not efficient.